下承式系杆钢拱桥拱脚应力及极限承载力

下承式系杆钢拱桥拱脚是全桥受力关键的部位之一，在正常使用过程中可能会发生强度破坏，从而引起桥梁的整体破坏。为了研究拱脚的受力性能，本文以深圳空港新城跨截流河3号景观桥项目为研究背景，通过有限元软件ANSYS建立拱脚壳单元有限元模型，考虑材料非线性及位移非线性，对4种正常使用荷载工况作用进行应力及极限承载力分析，得出了该部位的详细应力分布情况。结果表明：在正常使用最不利工况下，拱脚整体平均应力水平小于70 MPa，保证了拱脚在正常使用时不屈服；在极限荷载作用下，拱脚腹板底部大范围进入屈服，整体呈现塑性屈服破坏，屈服后拱脚无法继续承载，其极限荷载系数为4.71，拱脚受力合理，满足设计要求；最后给出合理的工程建议，为同类工程提供参考。

Stress and ultimate carrying capacity research of abutment of through tied bar steel arch-bridge

The abutment of through tied bar steel arch-bridge is the most important part of the bridge, so strength failure may occur during the normal service period, thus causing the overall damage of the bridge. In order to study the mechanical performance of the abutment, this paper takes the third landscape bridge across the river closure in Shenzhen airport metro as the research background, the shell finite element model of abutment was established by using the general finite element software ANSYS, considering material nonlinearity and displacement nonlinearity, the stress and ultimate bearing capacity of 4 load cases under the combination of the load conditions in serviceability states were analyzed, and the stress distribution of the abutment were obtained. The results show that under the most unfavorable case of serviceability states, the average stress of the abutment is less than 70 MPa, which ensures that the abutment will not yield in serviceability states; Under ultimate load, the bottom of the abutment will yield in a large range, which shows the plastic yield failure effect of the abutment as a whole. After yielding, the abutment cannot continue to carry load, and its ultimate load coefficient is 4.71. The abutment is safe and reasonable for loading, which meets the design requirements; Finally, reasonable engineering suggestions are given to provide a reference for similar projects.